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May 19, 2015 - A Look At The New Commandlinefu
I've put together a short writeup on what kind of newness you can expect from the next iteration of clfu. Check it out here.
March 2, 2015 - New Management
I'm Jon, I'll be maintaining and improving clfu. Thanks to David for building such a great resource!

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Psst. Open beta.

Wow, didn't really expect you to read this far down. The latest iteration of the site is in open beta. It's a gentle open beta-- not in prime-time just yet. It's being hosted over at UpGuard (link) and you are more than welcome to give it a shot. Couple things:

  • » The open beta is running a copy of the database that will not carry over to the final version. Don't post anything you don't mind losing.
  • » If you wish to use your user account, you will probably need to reset your password.
Your feedback is appreciated via the form on the beta page. Thanks! -Jon & CLFU Team

uniq for unsorted data

Terminal - uniq for unsorted data
awk '!_[$0]++{print}'
2009-02-06 09:52:35
User: dz
Functions: awk
uniq for unsorted data


There are 3 alternatives - vote for the best!

Terminal - Alternatives

Know a better way?

If you can do better, submit your command here.

What others think

Maybe I'm missing something, but:

a - I can't see how this works

b - it doesn't seem to work

...Create 3 line file test.txt:

'$ cat test.txt:




'$ awk '!_[$0]++{print}' test.txt




Am I being thick?

Comment by g__j 402 weeks ago

How about:

sort -u
Comment by systemj 402 weeks ago

g__j: it does 'uniq' but without requiring (or doing) sorting;

cat >test






awk '!_[$0]++{print}' < test




You can actually shorten it to:

awk '!_[$0]++'
Comment by porges 402 weeks ago

>>How about:

>>sort -u

I think this has several advantages:

* No need for the overhead of a sort

* Can be embedded in an awk conditional statement. for example:

printf "a\nb\na\nc\na\nc\n" | awk '{if(!_[$0]++){print}}'

* Can be inverted. To show only values that have been seen before. For example:

printf "a\nb\na\nc\na\nc\n" | awk '{if(_[$0]++){print}}'
Comment by unixmonkey3280 386 weeks and 3 days ago

Your point of view

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